What is the Difference Between Targeted and Untargeted Proteomics?

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The main difference between targeted and untargeted proteomics lies in the scope of their analysis. Here are the key differences between the two approaches:

Targeted Proteomics:

  • Focuses on identifying and absolutely quantifying one protein or a specific group of proteins in a sample.
  • Requires careful selection of peptides and method development, which can be time-consuming and labor-intensive.
  • Once a method is developed and verified, it can be applied to an unlimited number of samples.
  • Suitable for validation and implementation of biomarkers.
  • Provides more precise and accurate results.

Untargeted Proteomics:

  • Aims to comprehensively identify and characterize the relative abundances of all proteins in a sample.
  • Does not target a specific protein or peptide for its analysis, making it a more global analysis.
  • Can identify and measure many proteins, including novel proteins.
  • Less sensitive than targeted proteomics but can produce both qualitative and quantitative data.
  • Better suited for early stages of biomarker discovery and hypothesis generation.

In summary, targeted proteomics is focused on specific proteins or peptides, providing accurate quantification and validation of biomarkers, while untargeted proteomics aims to identify and characterize all proteins in a sample, making it more suitable for discovery and hypothesis generation.

Comparative Table: Targeted vs Untargeted Proteomics

Based on the search results, a table comparing targeted and untargeted proteomics can be created as follows:

Feature Targeted Proteomics Untargeted Proteomics
Definition Determines the presence and quantity of a specific protein or peptide in a complex mixture of proteins. Analyzes all proteins in a sample without targeting specific proteins or peptides.
Sensitivity More sensitive. Less sensitive.
Specificity Highly specific. Not as specific.
Uses Verifying knockdown targets, checking the presence of specific proteins in cell lysates or cerebral fluid. Identifying and measuring many proteins, including novel proteins.
Mass Spectrometry Triple quadrupole mass spectrometer (QQQ). High-resolution scans for data-independent acquisition (DIA).
Sample Input Measurements require less sample input. Can identify and measure many proteins using limited sample input.
Sample Preparation Fewer preparation steps. More preparation steps.

Targeted proteomics focuses on the presence and quantity of specific proteins or peptides, while untargeted proteomics analyzes all proteins in a sample. Targeted proteomics is more sensitive and specific, but untargeted proteomics can identify and measure many proteins, including novel proteins.